These studies are directed at the analysis and synthesis of molecular assemblies with rare amino acids, for instance (a) synthesis of precursors of rings A and B of nisin-a peptide with alpha, beta-unsaturated and thioether amino acids- and the synthesis of these two cyclic structures; (b) actions of peptides based on nisin and/or linear gramicidins on neonatal and neoplastic tissue; (c) synthesis of analogs of the gramicidins A, B, and C, and correlation of their structures with ion-transport across lipid bilayers; (d) synthesis of peptides with agonistic and antagonistic effects on fertility regulating hormones, including large-scale preparation of luteinizing hormone releasing factor (LRF) for clinical purposes; (e) exploration of dehydro-alanine resins for synthesis of peptide amides; (f) synthesis of analogs of opioid peptides with agonist and/or antagonist properties; (g) synthesis of analogs of the pentapeptide L-Phe-D-Leu-L-Phe-Leu-L-Phe L-Phe-D-Leu-L-Phe-D-Leu-L-Phe with chemotactic and antichemotactic characteristics; (h) structural investigation of the heterodetic pentacyclic peptides CINNAMYCIN and DURAMYCIN; (i) development of new techniques for peptide synthesis, amino acid analysis and nonenzymatic cleavage of the peptide bond; (j) synthesis of partial sequences of cholecystokinin and the correlation of structure and function of these peptides.